Registration Dossier

Ecotoxicological information

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1997-02-21 to 1997-03-28
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was well conducted by a GLP-compliant laboratory and according to an OECD guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD 202 "Acute immobilization test and reproduction test of water flea" (1984)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Specific details on test material used for the study:
- Name of test material (as cited in study report): 3-methyl-1,5-pentanediol
- Molecular formula: C6H14O2
- Molecular weight: 118.17
- Physical state: Colorless clear liquid
- Analytical purity: 99.8%
- Impurities (identity and concentrations): Water content 0.04%; Acid (as CH3COOH) less than 0.02%
- Lot/batch No.: WDK5104
- Storage condition of test material: stored in a refrigerator in Kurume Laboratory; stable under storage conditions, tested with IR
- Other: Supplier: Wako Pure Chemicals Industries Ltd.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
For each test medium, aliquot of samples was collected from the middle part of each of the test vessels, mixed, and analysed, directly or after dilution, by GC, 6 times during the whole exposure period (3 times just before and after water change), (for the samples before water changes, feed was removed by centrifuge, 10 min at 3000 rpm). For this analysis a standard solution (conc. 50 mg/L) was also measured and used to quantify the amount by peak area ratio.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was dissolved in de-chlorinated tap water to produce a stock solution of 1,000 mg/L.
The stock solution was further diluted with tap water to gain 3 concentration levels as used in the test (10, 50, 25 mg/L).

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Source: The original was purchased from U.S. EPA Environmental Research Laboratory, Duluth and subcultured in the Kurume laboratory
- Age of parental stock (mean and range, SD): 2 ~ 4 weeks (parent of immatures from subculture)
- Age at study initiation (mean and range, SD): immature aged 24 hours or less
- Feeding during test: Yes
- Food type: Unicellar algae (Chlorella Vulgaris); centrifuged by replacing with dilution water
- Amount:0.1 ~ 0.2 mgC(organic carbon content)/water flea (The amount was changed within this range depending on the growth stage of water feleas)
- Frequency: daily

ACCLIMATION
- Acclimation conditions (same as test or not): Same
- Type and amount of food: see above
- Feeding frequency: see above
-Culture density: 10 water fleas/800 mL culture water
- Health during acclimation (any mortality observed): batch with high death rate or sleeping eggs or males were not used for the test.

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
21 d

Test conditions

Test temperature:
19.9 - 20.5 °C
pH:
7.2 - 7.7
Dissolved oxygen:
6.9 - 8.8 mg/L
Nominal and measured concentrations:
100, 50, 25 mg/L nominal
measured: 97.2 ~ 103% of nominal value at the time of preperation of the test solution
measured: 91.8 - 106% of nominal value after 2 ~ 3 days (before water change)
Details on test conditions:
TEST SYSTEM
-Test vessel: 1000 mL glass vessel (diameter 12.0 cm, height 12.5 cm)
- Renewal rate of test solution (frequency/flow rate): 3 times a week; test organisms were placed into fresh test solutions three times a week
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Amount of test solution: 800 mL/vessel
- Biomass loading rate: 40 water fleas/L replicate


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated water; tap water was dechlorinated and treated by activated carbon. Before using the dilution water, aeration was fully carried out.
Dilution water chemistry:
- pH: 7.7
- Total hardness (converted to CaCO3): 55.6 mg/L
- COD: 0.2 mg/L
- Metals: not detected: total mercury, copper, cadmium, zinc, lead, aluminium, nickel, total chromium, manganese, tin. 0.05 mg/L Iron
- Pesticides: not detected
- Free chlorine: not detected
- Alkalinity: 37.5 mg/L
- Conductivity: 171 µs/cm
- Culture medium different from test medium: no


OTHER TEST CONDITIONS
- Photoperiod: 16 - 8 hour light-dark photocycle
- Light intensity: room light
- Test temperature: 20 +- 1°C (adjusted by Thermostat)
- Intervals of water quality measurement: Water temperature, dissolved oxygen concentration, and pH for all test medium (1 test vessel each) were measured in total 10 times (5 times before and after water change) during exposure period.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Parent water fleas: Number of live parents, number of immobilized, size, and appearance were measured everyday, by comparing against the control. Dead parents were removed after counting.
- Produced juveniles: Number of dead and live juveniles, and generation of sleeping eggs were measured before water changes. The juveniles were removed after counting. First brood production day was recorded.




RANGE-FINDING STUDY
From the results of acute immobilization test [OECD 202 Part I entered in the endpoint robust study summary 6.1.3 Kurume (1997); 91742; 48h EiC50 >1000 mg/L] and preliminary test results, the test concentration were set at 100, 50, 25 mg/L
Reference substance (positive control):
yes
Remarks:
Potassium dichromate, reagent ultra pure grade; Wako Pure Chemicals Industries Ltd.

Results and discussion

Effect concentrationsopen allclose all
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
>= 100 mg/L
Nominal / measured:
nominal
Basis for effect:
reproduction
Remarks:
on cumulative number of juveniles produced after 21 day, per parent
Duration:
21 d
Dose descriptor:
LOEC
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Basis for effect:
reproduction
Remarks:
on cumulative number of juveniles produced after 21 day, per parent
Duration:
21 d
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Basis for effect:
reproduction
Remarks:
inhibition
Duration:
21 d
Dose descriptor:
LC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Basis for effect:
mortality
Remarks:
for parent water fleas
Details on results:
- Mortality of parent animals: no
- Body length and weight of parent animals: no difference of size and conditions of Daphnia was observed between the control and the test medium
- Time to first brood release or time to hatch: day 7 for control and all test concentrations
- Effect concentrations exceeding solubility of substance in test medium: no
Results with reference substance (positive control):
confirmation of sensitivity: EiC50(48 hr) by reference substance potassium dichromate, reagent ultra pure grade was 0.283 mg/L. It has not been described whether the data are historical reference data of the Kurume laboratory or the U.S. EPA Environmental Research Laboratory.

Any other information on results incl. tables

Nominal concentrations: 25, 50 and 100 mg/L
Measured concentrations: 

Nominal concentration      Concentration of 
(mg/L)                 3-metyl-1,5-pentanediol (mg/L)
                          Range           Mean
Control                   n. d.           n. d.
25.0                   23.2 - 25.7        24.4
50.0                   45.9 - 51.7        49.6
100                    96.3 - 106          102
n. d. :<5.00 mg/L



Biological observations
Cumulative numbers of dead parental Daphnia:

Nominal concentration       Cumulative number of 
(mg/L)            dead parental Daphnia Exposure time (day)
                          7        14         21
   0                    0(0)      0(0)       0(0)
  25.0                  0(0)      0(0)       2(5.0%)
  50.0                  0(0)      0(0)       0(0)
 100                    0(0)      0(0)       1(2.5%)
There is no statisitcally significant difference from control for mortality

Time of the first production of young: 7 days for control and all testconcentrations


Mean cumulative numbers of young produced per adult: 

Nominal concentration      Mean cumulative numbers of young  S.D
(mg/L)                       produced per adult at 21 days
      0                              86.1                     13.9
     25.0                           102                      11.9             
     50.0                           109                        4.4
    100                              98.7                      9.8

There is no statisitcally significant difference from control for number of juveniles produced


Was control response satisfactory: Yes 

Applicant's summary and conclusion

Conclusions:
NOEC reproduction inhibition > = 100 mg/L
Executive summary:

This study was performed in compliance with OECD Guideline No. 202 (1984) Part II for reproduction with water fleas to test the substance MPD with the test concentration 100, 50 and 25 mg/L and control. Under the reported test conditions a LC50 of parent fleas in 21 days was > 100 mg/L. The ErC50 in 21 days was >100 mg/L and the LOECr in 21 days was >100 mg/L.